Bug 26039 - mandroid error XA0020 Unable to launch daemon
Summary: mandroid error XA0020 Unable to launch daemon
Alias: None
Product: Visual Studio Extensions
Classification: Xamarin
Component: Android ()
Version: 3.8
Hardware: PC Windows
: Highest critical
Target Milestone: ---
Assignee: Bugzilla
Depends on:
Reported: 2015-01-14 16:44 UTC by John Miller [MSFT]
Modified: 2015-08-06 18:30 UTC (History)
8 users (show)

Is this bug a regression?: ---
Last known good build:

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Description John Miller [MSFT] 2015-01-14 16:44:39 UTC

   User reports intermittent error when building a solution. Building each individual project in the solution does not seem to run into this issue. 

**Steps to Reproduce:**

   Nothing reliable yet. 

**Actual Results:**

   C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets(379,2): mandroid error XA0020: Unable to launch daemon.

**Expected Results:**

   No error. 

**Build Date & Platform:**

   XVS 3.8.150
   XA 4.20

**Additional Information:**

   Attached is full version info and logs from the case reporting this.
Comment 3 John Miller [MSFT] 2015-01-19 00:01:17 UTC
Having multiple Visual Studios open might cause this.
Comment 5 matthew.thomas 2015-07-28 15:48:33 UTC
Our team is also experiencing this without having multiple instances of Visual Studio open.
Comment 6 Jonathan Pryor 2015-07-30 22:53:08 UTC
The logs don't entirely make sense to me.

Firstly, there's this NullReferenceException:

> Xamarin.VisualStudio.Shell.ShellPackage Error: 0 : [2015-01-10 08:04:22.0] Background task error
> System.NullReferenceException: Object reference not set to an instance of an object.
>    at Xamarin.InsightsCore.PlatformServices.<>c__DisplayClass4.<GetDeviceInfoData>b__3()
>    at System.Threading.Tasks.Task`1.InnerInvoke()
>    at System.Threading.Tasks.Task.Execute()

Xamarin.Android does not currently use Insights, so this should be unrelated.

Then there's this SocketException:

> Mono.AndroidTools.AndroidLogger Error: 0 : [2015-01-13 17:04:33.2] [E:]:                     Error in device tracker
> System.Net.Sockets.SocketException (0x80004005): No connection could be made because the target machine actively refused it
>    at System.Net.Sockets.Socket.EndConnect(IAsyncResult asyncResult)
>    at System.Net.Sockets.TcpClient.EndConnect(IAsyncResult asyncResult)
>    at Mono.AndroidTools.Adb.AdbClient.EndConnect(IAsyncResult asyncResult)
>    at Mono.AndroidTools.TrackDeviceTask.Connected(IAsyncResult r)

This is generated because the connection to `adb` was lost, which could only be a problem if using `adb` in the first place. (Are you using `msbuild  /t:Install`? Perhaps you could try `msbuild /t:SignAndroidPackage`?)